Method for constructing an insulated roof structure



May 26, 1970 J. D. sTuDzlNsKl 3,513,614

METHOD FOR CONSTRUCTING AN INSULATED ROOF' STRUCTURE Filed Feb. 5, 1969FIG-2 FIG-I y m/l/E/vrw?l JAMES D. STUDZINSKI 75 c f4 JA j 74 BY 7 2 ATTORNE YS United States Patent Office 3,513,614 Patented May 26, 19703,513,614 METHOD FOR CONSTRUC'I'ING AN INSULATED ROOF STRUCTURE James D.Studzinski, Dayton, Ohio, assignor to Illini Building Systems, Inc.,Dayton, Ohio, a corporation of Ohio Filed Feb. 3, 1969, Ser. No. 796,038Int. Cl. E04b 1 80, 7/02 U.S. Cl. 52--743 1 Claim ABSTRACT OF THEDISCLOSURE BACKGROUND OF THE INVENTION In the construction of a roof fora metal building, usually a plurality of laterally extending roof orwedge beams are supported at longitudinally spaced intervals defining aplurality of laterally extending bays each having a predetermined width,as for example, 18, 20 or 24 feet. A plurality of longitudinallyextending purlins are mounted on the wedge beams and are spacedlaterally at predetermined intervals, as for example, 5 feet. Usually,the purlins have a C-shaped or a Z-shaped cross-sectional configuration,and the ends of the lower flange of each purlin are rigidly secured tothe adjacent wedge beams by suitable screws or rivets.

After the purlins are secured to the wedge beams, strips of insulationmaterial are unrolled laterally across the purlins after which aplurality of overlapping ribbed metal roof panels are secured to theupper flanges of the purlins thereby compressing the insulation materialbetween the underneath surfaces of the roof panels and the top surfacesof the purlins. If the day selected for installing the roof happens tobe Windy or gusty, there is considerable difficulty in positioning andretaining each strip of insulation material while the overlying metalroof panels are positioned and secured to the adjacent purlins by eitherscrews or rivets. Moreover, it is necessary to handle alternately bothmetal roof panels and rolls of insulation material, usually resulting inconsiderable labor inefficiency in the assembly of the roof.Furthermore, it is not uncommon for the insulation material to sagbetween the purlins thereby presenting an undesirable appearance fromwithin the building and also creating air spaces between the roof panelsand the insulation material Where humid air can collect and condense onthe underneath surfaces of the metal roof panels.

SUMMARY OF THE INVENTION The present invention is directed to animproved roof structure especially suited for metal buildings and amethod of constructing the roof structure which significantly increasesthe labor efliciency for assembling a roof by enabling the insulationpanels to be installed after the roof panels are installed. Thus on dayswhen the Weather is clear and favorable for working outside, the metalroof panels can be installed, and the installation of the insulationpanels can be delayed till a day when the weather is unfavorablel forworking outside. The roof structure of the invention also provides forretaining the insulation panels adjacent the underneath surface of theoverlying roof panels so that there are no air spaces whereby moisturecan condense on the underneath surfaces of the roof panels.

In accordance with one embodiment of the invention, an elongatedchannel-'shaped cap member constructed of either metal or plastic ismounted on the upper flange of each purlin. -Each cap member includesoutwardly projecting and longitudinally extending coplanar flanges whichprovide support surfaces spaced under the roof panels by a predetermineddistance. A strip of insulation material is attached to the uppersurface of each cap member and is compressed when the metal roof panelsare secured to the purlins by either screws or rivets.

After the roof panels are installed, a plurality of elastically flexibleinsulation panels are positioned between the purlins, and eachinsulation panel is flexed while opposite edge portions are insertedonto the support surfaces provided by the flanges of the adjacent capmembers. Preferably, each insulation panel comprises a pad of fiberglass having one side covered by a sheet of decorative vinyl materialwhich also serves las a vapor barrier. In accordance with anotherembodiment of the invention, the support surfaces for the insulationpanels are provided by strips of insulation material which arepositioned adjacent the sides of each purlin and are supported by alongitudinally extending trim member attached to the lower surface ofthe purlin.

BRIEF DESCRIPTION OF TH=E DRAWINGS FIG. 1 is a somewhat schematicvertical section of a building having a roof constructed in accordancewith the invention;

FIG. 2 is an enlarged fragmentary section of the portion of the roofindicated in FIG. 1;

FIG. 3 is a fragmentary perspective view of the roof portion shown inFIG. 2; and

FIG. 4 is a fragmentary section of a roof constructed in accordance withanother embodiment of the invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS `attaching vertical metal wallpanels 16.

A plurality of longitudinally extending purlins 20 are mounted on thewedge beams 14 in parallel spaced relation and between longitudinallyextending eave struts 21. Each purlin 20 extends the length of one bayand preferably has a Z-shaped cross-sectional configuration formed by alongitudinally extending upper flange 22 connected to a lower flange 23by a web portion 24. The end portions of the lower flange 23 of eachpurlin 20 are secured to the Isupporting Wedge beams 14 by either rivetsor screws (not shown). A longitudinally extending rib portion 26projects from each flange 22 and 23 in parallel spaced relation to theweb portion 24. Each eave strut 21 has a C-shaped cross-sectionalconfiguration and a height equal to that of the purlins 20.

An elongated cap member 35 is mounted on each purlin 20 and includes aninverted channel portion 36 and outwardly projecting longitudinallyextending flanges 38 forming coplanar support surfaces 40. Preferably,the channel portion 36 of each cap member 35 includes a series ofprepunched holes 41 which align with corresponding prepunched holes 42formed within the upper ange portion 22 of the adjacent purlin 20.Similar cap members with only one flange 38 are mounted on the eavestruts 21.

An elongated strip 45 of insulation material is secured to the uppersurface of each cap member 35 by a suitable cement. Preferably, eachstrip 45 of insulation material is formed of fiberglass and has aminimum thickness of approximately one inch. A plurality of ribbed metalroof panels 50 are mounted on the purlins 20, and the edge portions ofadjacent panels are overlapped to form a water tight seal therebetween.Preferably, each roof panel 50 has prepunched holes which align with theholes 41 and 42, and a series of rivets 52 secure the roof panels 50 tothe purlins 2t) compressing the insulation strips 45 between theunderneath surafces of the roof panels and the top surfaces of thepurlin cap members 35. The metal roof panels 50 may also be secured tothe purlins by screws which are usually either of the self-drilling typeor the self-tapping type.

A plurality of insulation panels 55 are positioned between the purlins20 and opposite edge portions of each insulation panel 55 are supportedby the surfaces 40 of the opposing adjacent flanges 38 which are spacedfrom the underneath surfaces of the roof panels 50 by a distanceslightly less than the thickness of the insulation panels 55. Thus eachinsulation panel 55 is supported in firm contact with the underneathsurface of the overlying roof panels 50 to avoid dead air spaces betweenthe insulation panels 55 and the roof panels 50.

Each insulation panel 55 is formed by laminating a sheet of decorativevinyl 58 to a liberless pad 59 thereby producing a semi-rigid panelwhich is elastically exible so that when the panel is folded andreleased, it will snap back to its original planar condition. One suchinsulation panel which provides satisfactory performance is produced byJohns-Manville and includes tongue and groove edge portions for formingthe laterally extending unsupported joints between adjacent purlins 20within each bay.

The elastic iiexibility of each insulation panel 55 enables the panelsto be installed after the roof panels 50 are secured to the purlins 20.That is, each roof insulation panel 55 is partially folded in the centerwhile the opposite edge portions are inserted into the sapces definedbetween the anges 38 of the adjacent purlin cap members and theoverlying roof panels 50. When the insulation panel 55 is released, itsnaps into a position in iirm contact with the underneath surface of theoverlying roof panels.

Referring to FIG. 4 which shows another embodiment of the invention, themetal roof panels 50 are secured directly to the upper flanges 22 of thepurlins 20' such as by the rivets 41 shown in FIG. 2. A plurality ofinsulation panels 55 are supported adjacent the underneath surfaces ofthe roof panels 50 by the edge support surfaces of a pair of strips 65of insulation material positioned adjacent opposite sides of each purlin20. Preferably, each insulation panel 55' has a vinyl covering 58', andeach strip 65 of insulation material has a similar vinyl covering 68 toprovide a decorative appearance for the underneath side of the roof.

The insulation strips 65 are supported adjacent the sides of each purlin20 by a decorative trim strip 70 having generally an inverted T-shapedcross-sectional configuration. Each trim strip 70 includes one flangeportion 72 which extends adjacent the underneath surface of the lowerflange 23 of the corresponding purlin 20 which supports one of theinsulation strips 65. Another flange portion 72 of each trim strip 70forms a support for the other insulation strip 65. A longitudinallyextending rib or iiange 74 projects upwardly from each ange portion 72of each trim strip 70 and serves to retain the adjacent insulation strip65. The trim strips 70 may be formed as either a plastic or a metalextrusion and are secured to the purlins 20 by longitudinally spacedrivets 75 or suitable screws.

From the drawing and the above description, it is apparent that a roofstructure constructed in accordance with the present invention providesdesirable features and advantages. As a primary advantage, the roofstructure of the invention `provides for installing the insulationpanels 55 or 55 after the roof panels S0 are installed. Thus it isunnecessary to handle insulation panels and roof panels alternately orsimultaneously while installing the roof, which is especiallyundesirable when the roof of the building is being installed on a windyor gusty day. Thus, the roof panels 50 can be efficiently installed on aday when the weather is favorable for working outside and theinstallation of the insulation panels 55 or 55 can be postponed until aday when the weather is not favorable such as a rainy, windy or snowyday.

The combination of the purlin cap members 35 and the elasically flexibleinsulation panels 55 also enables each insulation panel 55 to beinstalled in position adjacent the underneath surfaces of the overlyingroof panels so that there is no air space where humid air can collectand condense on the underneath surface of the roof panels. Theinsulation strip on each purlin cap member 35 has been found helpful inavoiding the condensation of moisture on the underneath surface of theflange 22 of each purlin 20.

In the embodiment shown in FIG. 4, each insulation panel 55 may beplaced in position adjacent the underneath surfaces of the overlyingroof panels after which the supporting insulation strips 65 are placedin position adjacent the sides of the corresponding purlins 20. Inaddition, the vinyl coverings 58' on the insulation panels cooperatewith the vinyl covering 68 on the insulation strips and the trim strips70 to provide the roof with a decorative inside appearance with theinsulated purlins providing a beam-like effect.

While the forms of apparatus and method herein described constitutepreferred embodiments of the invention, it is to be understood that theinvention is not limited to these precise forms of apparatus and method,and that changes may be made therein Without departing from the scopeand spirit of the invention.

What is claimed is:

1. An improved method of constructing a roof on a building having aplurality of parallel spaced elongated purlins, comprising the steps ofsecuring longitudinally extending strips of insulation material to theupper surfaces of a plurality of elongated cap members each havingoutwardly extending coplanar flanges, mounting said cap members on theupper surfaces of said purlins with said anges projecting laterallybetween said purlins and below the upper surfaces of said purlins by apredetermined distance, positioning a plurality of substantially rigidroof panels over said purlins and said strips of insulation material,securing said roof panels to said purlins with fasteners extendingthrough said cap members, partially folding a plurality of semi-rigidand elastically exible insulation panels each having a thicknesssubstantially equal to said predetermined distance, inserting oppositeedge portions of each said insulation panel between the adjacent saidanges of said cap members and the overlying said roof panel, andreleasing each said insulation panel to position said insulation panelin contact with the underneath surface of the overlying said roof panel.

References Cited UNITED STATES PATENTS 2,054,531 9/1936 Zand 52-7432,102,902 12/ 1937 Lenke 52-395 2,299,908 10/ 1942 Leash 52-741 X (Otherreferences on following page) UNITED STATES PATENTS 627,013 7/1949 GreatBritain. 2,590,687 3/1952 Grafton 52-460 X 672297 5/1952 Great Bmam'2,799,232 7/1957 Jaeger 52- 409 OTHER REFERENCES 2,832,300 4/1958Jacobson 52-579 Metal Building Review, Maren 196s, pages 16 and 17.3,141,206 7/1964 Stephens 52-406 X 5 3,173,224 3/ 1965 Aagaard 52--11ALFRED C. PERHAM, Primary Examiner FOREIGN PATENTS U S C1. XR

589,754 6/ 1947 Great Britain. 52-404, 478

